Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in /var/www/usonboard.com/vendor/microsoft/kiota-serialization-json/tests/JsonSerializationWriterTest.php:19 Stack trace: #0 {main} thrown in /var/www/usonboard.com/vendor/microsoft/kiota-serialization-json/tests/JsonSerializationWriterTest.php on line 19